"Music is liquid architecture, architecture is frozen music." The dictum by German writer Johann Wolfgang von Goethe still stands true today, even if modern musicians and architects may work in different ways. The Philadelphia Orchestra, which first visited China in 1973, has returned to China for the 13th time to perform the sounds of friendship that have spanned half a century. How do sister cities usually go about bolstering ties and exchanges? As bilateral sister-city relationships continue to flourish between China and the United States, where there are now more than 200 twinned pairings, the two capitals set an example by establishing sister-city ties as early as 1984. Back then, the Beijing Municipal Government dispatched a team of construction experts led by Ma Bingjian to help build a landmark in the Chinatown area of Washington, D.C. CGTN host Julian Waghann recently interviewed Ma and asked him to reflect on his fulfilling experience of bringing communities from the two countries closer together.